2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Optimal reductions and helper functions.
24 * @author Sebastian Buchwald
29 #include "adt/array.h"
35 #include "html_dumper.h"
40 #include "pbqp_edge.h"
41 #include "pbqp_edge_t.h"
42 #include "pbqp_node.h"
43 #include "pbqp_node_t.h"
49 pbqp_edge_t **edge_bucket;
50 pbqp_edge_t **rm_bucket;
51 pbqp_node_t **node_buckets[4];
52 pbqp_node_t **reduced_bucket = NULL;
53 pbqp_node_t *merged_node = NULL;
54 static int buckets_filled = 0;
56 static void insert_into_edge_bucket(pbqp_edge_t *edge)
58 if (edge_bucket_contains(edge_bucket, edge)) {
59 /* Edge is already inserted. */
63 edge_bucket_insert(&edge_bucket, edge);
66 static void insert_into_rm_bucket(pbqp_edge_t *edge)
68 if (edge_bucket_contains(rm_bucket, edge)) {
69 /* Edge is already inserted. */
73 edge_bucket_insert(&rm_bucket, edge);
76 static void init_buckets(void)
80 edge_bucket_init(&edge_bucket);
81 edge_bucket_init(&rm_bucket);
82 node_bucket_init(&reduced_bucket);
84 for (i = 0; i < 4; ++i) {
85 node_bucket_init(&node_buckets[i]);
89 void free_buckets(void)
93 for (i = 0; i < 4; ++i) {
94 node_bucket_free(&node_buckets[i]);
97 edge_bucket_free(&edge_bucket);
98 edge_bucket_free(&rm_bucket);
99 node_bucket_free(&reduced_bucket);
104 void fill_node_buckets(pbqp_t *pbqp)
109 node_len = pbqp->num_nodes;
112 ir_timer_t *t_fill_buckets = ir_timer_new();
113 ir_timer_start(t_fill_buckets);
116 for (node_index = 0; node_index < node_len; ++node_index) {
118 pbqp_node_t *node = get_node(pbqp, node_index);
122 degree = pbqp_node_get_degree(node);
124 /* We have only one bucket for nodes with arity >= 3. */
129 node_bucket_insert(&node_buckets[degree], node);
135 ir_timer_stop(t_fill_buckets);
136 printf("PBQP Fill Nodes into buckets: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_fill_buckets) / 1000.0);
140 static void normalize_towards_source(pbqp_edge_t *edge)
143 pbqp_node_t *src_node;
144 pbqp_node_t *tgt_node;
150 unsigned new_infinity = 0;
152 src_node = edge->src;
153 tgt_node = edge->tgt;
155 src_vec = src_node->costs;
156 tgt_vec = tgt_node->costs;
158 src_len = src_vec->len;
159 tgt_len = tgt_vec->len;
165 /* Normalize towards source node. */
166 for (src_index = 0; src_index < src_len; ++src_index) {
167 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
170 if (src_vec->entries[src_index].data == INF_COSTS) {
171 pbqp_matrix_set_row_value(mat, src_index, 0);
175 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
176 src_vec->entries[src_index].data = pbqp_add(
177 src_vec->entries[src_index].data, min);
179 if (min == INF_COSTS) {
187 unsigned edge_len = pbqp_node_get_degree(src_node);
189 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
190 pbqp_edge_t *edge_candidate = src_node->edges[edge_index];
192 if (edge_candidate != edge) {
193 insert_into_edge_bucket(edge_candidate);
199 static void normalize_towards_target(pbqp_edge_t *edge)
202 pbqp_node_t *src_node;
203 pbqp_node_t *tgt_node;
209 unsigned new_infinity = 0;
211 src_node = edge->src;
212 tgt_node = edge->tgt;
214 src_vec = src_node->costs;
215 tgt_vec = tgt_node->costs;
217 src_len = src_vec->len;
218 tgt_len = tgt_vec->len;
224 /* Normalize towards target node. */
225 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
226 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
229 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
230 pbqp_matrix_set_col_value(mat, tgt_index, 0);
234 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
235 tgt_vec->entries[tgt_index].data = pbqp_add(
236 tgt_vec->entries[tgt_index].data, min);
238 if (min == INF_COSTS) {
246 unsigned edge_len = pbqp_node_get_degree(tgt_node);
248 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
249 pbqp_edge_t *edge_candidate = tgt_node->edges[edge_index];
251 if (edge_candidate != edge) {
252 insert_into_edge_bucket(edge_candidate);
259 * Tries to apply RM for the source node of the given edge.
261 * Checks whether the source node of edge can be merged into the target node of
262 * edge, and performs the merge, if possible.
264 static void merge_source_into_target(pbqp_t *pbqp, pbqp_edge_t *edge)
267 pbqp_node_t *src_node;
268 pbqp_node_t *tgt_node;
279 src_node = edge->src;
280 tgt_node = edge->tgt;
282 src_vec = src_node->costs;
283 tgt_vec = tgt_node->costs;
285 src_len = src_vec->len;
286 tgt_len = tgt_vec->len;
288 /* Matrizes are normalized. */
294 mapping = NEW_ARR_F(unsigned, tgt_len);
296 /* Check that each column has at most one zero entry. */
297 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
298 unsigned onlyOneZero = 0;
300 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
303 for (src_index = 0; src_index < src_len; ++src_index) {
304 if (src_vec->entries[src_index].data == INF_COSTS)
307 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
310 /* Matrix entry is finite. */
317 mapping[tgt_index] = src_index;
321 /* We know that we can merge the source node into the target node. */
322 edge_len = pbqp_node_get_degree(src_node);
329 if (pbqp->dump_file) {
331 sprintf(txt, "Merging n%d into n%d", src_node->index, tgt_node->index);
332 dump_section(pbqp->dump_file, 3, txt);
336 /* Reconnect the source's edges with the target node. */
337 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
338 pbqp_edge_t *old_edge = src_node->edges[edge_index];
339 pbqp_edge_t *new_edge;
340 pbqp_matrix_t *old_matrix;
341 pbqp_matrix_t *new_matrix;
342 pbqp_node_t *other_node;
345 unsigned other_index;
349 if (old_edge == edge)
352 old_matrix = old_edge->costs;
354 if (old_edge->tgt == src_node) {
355 other_node = old_edge->src;
356 other_len = old_matrix->rows;
359 other_node = old_edge->tgt;
360 other_len = old_matrix->cols;
362 other_vec = other_node->costs;
364 new_matrix = pbqp_matrix_alloc(pbqp, tgt_len, other_len);
366 /* Source node selects the column of the old_matrix. */
367 if (old_edge->tgt == src_node) {
368 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
369 unsigned src_index = mapping[tgt_index];
371 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
374 for (other_index = 0; other_index < other_len; ++other_index) {
375 if (other_vec->entries[other_index].data == INF_COSTS)
378 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[other_index*src_len+src_index];
382 /* Source node selects the row of the old_matrix. */
384 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
385 unsigned src_index = mapping[tgt_index];
387 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
390 for (other_index = 0; other_index < other_len; ++other_index) {
391 if (other_vec->entries[other_index].data == INF_COSTS)
394 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[src_index*other_len+other_index];
399 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
401 add_edge_costs(pbqp, tgt_node->index, other_node->index, new_matrix);
403 if (new_edge == NULL) {
404 reorder_node_after_edge_insertion(tgt_node);
405 reorder_node_after_edge_insertion(other_node);
408 delete_edge(old_edge);
410 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
411 simplify_edge(pbqp, new_edge);
413 insert_into_rm_bucket(new_edge);
422 * Tries to apply RM for the target node of the given edge.
424 * Checks whether the target node of edge can be merged into the source node of
425 * edge, and performs the merge, if possible.
427 static void merge_target_into_source(pbqp_t *pbqp, pbqp_edge_t *edge)
430 pbqp_node_t *src_node;
431 pbqp_node_t *tgt_node;
442 src_node = edge->src;
443 tgt_node = edge->tgt;
445 src_vec = src_node->costs;
446 tgt_vec = tgt_node->costs;
448 src_len = src_vec->len;
449 tgt_len = tgt_vec->len;
451 /* Matrizes are normalized. */
457 mapping = NEW_ARR_F(unsigned, src_len);
459 /* Check that each row has at most one zero entry. */
460 for (src_index = 0; src_index < src_len; ++src_index) {
461 unsigned onlyOneZero = 0;
463 if (src_vec->entries[src_index].data == INF_COSTS)
466 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
467 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
470 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
473 /* Matrix entry is finite. */
480 mapping[src_index] = tgt_index;
484 /* We know that we can merge the target node into the source node. */
485 edge_len = pbqp_node_get_degree(tgt_node);
492 if (pbqp->dump_file) {
494 sprintf(txt, "Merging n%d into n%d", tgt_node->index, src_node->index);
495 dump_section(pbqp->dump_file, 3, txt);
499 /* Reconnect the target's edges with the source node. */
500 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
501 pbqp_edge_t *old_edge = tgt_node->edges[edge_index];
502 pbqp_edge_t *new_edge;
503 pbqp_matrix_t *old_matrix;
504 pbqp_matrix_t *new_matrix;
505 pbqp_node_t *other_node;
508 unsigned other_index;
513 if (old_edge == edge)
516 old_matrix = old_edge->costs;
518 if (old_edge->tgt == tgt_node) {
519 other_node = old_edge->src;
520 other_len = old_matrix->rows;
523 other_node = old_edge->tgt;
524 other_len = old_matrix->cols;
526 other_vec = other_node->costs;
528 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
530 /* Target node selects the column of the old_matrix. */
531 if (old_edge->tgt == tgt_node) {
532 for (src_index = 0; src_index < src_len; ++src_index) {
533 unsigned tgt_index = mapping[src_index];
535 if (src_vec->entries[src_index].data == INF_COSTS)
538 for (other_index = 0; other_index < other_len; ++other_index) {
539 if (other_vec->entries[other_index].data == INF_COSTS)
542 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
546 /* Source node selects the row of the old_matrix. */
548 for (src_index = 0; src_index < src_len; ++src_index) {
549 unsigned tgt_index = mapping[src_index];
551 if (src_vec->entries[src_index].data == INF_COSTS)
554 for (other_index = 0; other_index < other_len; ++other_index) {
555 if (other_vec->entries[other_index].data == INF_COSTS)
558 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
563 new_edge = get_edge(pbqp, src_node->index, other_node->index);
565 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
567 if (new_edge == NULL) {
568 reorder_node_after_edge_insertion(src_node);
569 reorder_node_after_edge_insertion(other_node);
572 delete_edge(old_edge);
574 new_edge = get_edge(pbqp, src_node->index, other_node->index);
575 simplify_edge(pbqp, new_edge);
577 insert_into_rm_bucket(new_edge);
586 * Merge neighbors into the given node.
588 void apply_RM(pbqp_t *pbqp, pbqp_node_t *node)
595 edge_len = pbqp_node_get_degree(node);
597 /* Check all incident edges. */
598 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
599 pbqp_edge_t *edge = edges[edge_index];
601 insert_into_rm_bucket(edge);
604 /* ALAP: Merge neighbors into given node. */
605 while(edge_bucket_get_length(rm_bucket) > 0) {
606 pbqp_edge_t *edge = edge_bucket_pop(&rm_bucket);
608 /* If the edge is not deleted: Try a merge. */
609 if (edge->src == node)
610 merge_target_into_source(pbqp, edge);
611 else if (edge->tgt == node)
612 merge_source_into_target(pbqp, edge);
618 void reorder_node_after_edge_deletion(pbqp_node_t *node)
620 unsigned degree = pbqp_node_get_degree(node);
621 /* Assume node lost one incident edge. */
622 unsigned old_degree = degree + 1;
624 if (!buckets_filled) return;
626 /* Same bucket as before */
627 if (degree > 2) return;
629 /* Delete node from old bucket... */
630 node_bucket_remove(&node_buckets[old_degree], node);
632 /* ..and add to new one. */
633 node_bucket_insert(&node_buckets[degree], node);
636 void reorder_node_after_edge_insertion(pbqp_node_t *node)
638 unsigned degree = pbqp_node_get_degree(node);
639 /* Assume node lost one incident edge. */
640 unsigned old_degree = degree - 1;
642 if (!buckets_filled) return;
644 /* Same bucket as before */
645 if (old_degree > 2) return;
647 /* Delete node from old bucket... */
648 node_bucket_remove(&node_buckets[old_degree], node);
650 /* ..and add to new one. */
651 node_bucket_insert(&node_buckets[degree], node);
654 void simplify_edge(pbqp_t *pbqp, pbqp_edge_t *edge)
657 pbqp_node_t *src_node;
658 pbqp_node_t *tgt_node;
666 src_node = edge->src;
667 tgt_node = edge->tgt;
671 /* If edge are already deleted, we have nothing to do. */
672 if (is_deleted(edge))
676 if (pbqp->dump_file) {
678 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
679 dump_section(pbqp->dump_file, 3, txt);
683 src_vec = src_node->costs;
684 tgt_vec = tgt_node->costs;
686 src_len = src_vec->len;
687 tgt_len = tgt_vec->len;
694 if (pbqp->dump_file) {
695 fputs("Input:<br>\n", pbqp->dump_file);
696 dump_simplifyedge(pbqp, edge);
700 normalize_towards_source(edge);
701 normalize_towards_target(edge);
704 if (pbqp->dump_file) {
705 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
706 dump_simplifyedge(pbqp, edge);
710 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
712 if (pbqp->dump_file) {
713 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
725 void initial_simplify_edges(pbqp_t *pbqp)
731 ir_timer_t *t_int_simpl = ir_timer_new();
732 ir_timer_start(t_int_simpl);
736 if (pbqp->dump_file) {
737 pbqp_dump_input(pbqp);
738 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
742 node_len = pbqp->num_nodes;
746 /* First simplify all edges. */
747 for (node_index = 0; node_index < node_len; ++node_index) {
749 pbqp_node_t *node = get_node(pbqp, node_index);
756 edge_len = pbqp_node_get_degree(node);
758 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
759 pbqp_edge_t *edge = edges[edge_index];
761 /* Simplify only once per edge. */
762 if (node != edge->src) continue;
764 simplify_edge(pbqp, edge);
769 ir_timer_stop(t_int_simpl);
770 printf("PBQP Initial simplify edges: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
774 num determine_solution(pbqp_t *pbqp)
781 ir_timer_t *t_det_solution = ir_timer_new();
782 ir_timer_reset_and_start(t_det_solution);
792 file = pbqp->dump_file;
795 dump_section(file, 1, "4. Determine Solution/Minimum");
796 dump_section(file, 2, "4.1. Trivial Solution");
800 /* Solve trivial nodes and calculate solution. */
801 node_len = node_bucket_get_length(node_buckets[0]);
804 pbqp->num_r0 = node_len;
807 for (node_index = 0; node_index < node_len; ++node_index) {
808 pbqp_node_t *node = node_buckets[0][node_index];
810 node->solution = vector_get_min_index(node->costs);
811 solution = pbqp_add(solution,
812 node->costs->entries[node->solution].data);
816 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
817 dump_node(file, node);
824 dump_section(file, 2, "Minimum");
825 #if KAPS_USE_UNSIGNED
826 fprintf(file, "Minimum is equal to %u.", solution);
828 fprintf(file, "Minimum is equal to %lld.", solution);
834 ir_timer_stop(t_det_solution);
835 printf("PBQP Determine Solution: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
841 static void back_propagate_RI(pbqp_t *pbqp, pbqp_node_t *node)
850 edge = node->edges[0];
852 is_src = edge->src == node;
857 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
860 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
864 if (pbqp->dump_file) {
865 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
870 static void back_propagate_RII(pbqp_t *pbqp, pbqp_node_t *node)
872 pbqp_edge_t *src_edge = node->edges[0];
873 pbqp_edge_t *tgt_edge = node->edges[1];
874 int src_is_src = src_edge->src == node;
875 int tgt_is_src = tgt_edge->src == node;
876 pbqp_matrix_t *src_mat;
877 pbqp_matrix_t *tgt_mat;
878 pbqp_node_t *src_node;
879 pbqp_node_t *tgt_node;
886 src_node = src_edge->tgt;
888 src_node = src_edge->src;
892 tgt_node = tgt_edge->tgt;
894 tgt_node = tgt_edge->src;
897 /* Swap nodes if necessary. */
898 if (tgt_node->index < src_node->index) {
899 pbqp_node_t *tmp_node;
900 pbqp_edge_t *tmp_edge;
910 src_is_src = src_edge->src == node;
911 tgt_is_src = tgt_edge->src == node;
914 src_mat = src_edge->costs;
915 tgt_mat = tgt_edge->costs;
917 node_vec = node->costs;
919 row_index = src_node->solution;
920 col_index = tgt_node->solution;
922 vec = vector_copy(pbqp, node_vec);
925 vector_add_matrix_col(vec, src_mat, row_index);
927 vector_add_matrix_row(vec, src_mat, row_index);
931 vector_add_matrix_col(vec, tgt_mat, col_index);
933 vector_add_matrix_row(vec, tgt_mat, col_index);
936 node->solution = vector_get_min_index(vec);
939 if (pbqp->dump_file) {
940 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
944 obstack_free(&pbqp->obstack, vec);
947 void back_propagate(pbqp_t *pbqp)
950 unsigned node_len = node_bucket_get_length(reduced_bucket);
953 if (pbqp->dump_file) {
954 dump_section(pbqp->dump_file, 2, "Back Propagation");
958 for (node_index = node_len; node_index > 0; --node_index) {
959 pbqp_node_t *node = reduced_bucket[node_index - 1];
961 switch (pbqp_node_get_degree(node)) {
963 back_propagate_RI(pbqp, node);
966 back_propagate_RII(pbqp, node);
969 panic("Only nodes with degree one or two should be in this bucket");
975 void apply_edge(pbqp_t *pbqp)
977 pbqp_edge_t *edge = edge_bucket_pop(&edge_bucket);
979 simplify_edge(pbqp, edge);
982 void apply_RI(pbqp_t *pbqp)
984 pbqp_node_t *node = node_bucket_pop(&node_buckets[1]);
985 pbqp_edge_t *edge = node->edges[0];
986 pbqp_matrix_t *mat = edge->costs;
987 int is_src = edge->src == node;
988 pbqp_node_t *other_node;
991 assert(pbqp_node_get_degree(node) == 1);
994 other_node = edge->tgt;
996 other_node = edge->src;
1000 if (pbqp->dump_file) {
1002 sprintf(txt, "RI-Reduction of Node n%d", node->index);
1003 dump_section(pbqp->dump_file, 2, txt);
1004 pbqp_dump_graph(pbqp);
1005 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1006 dump_node(pbqp->dump_file, node);
1007 dump_node(pbqp->dump_file, other_node);
1008 dump_edge(pbqp->dump_file, edge);
1013 pbqp_matrix_add_to_all_cols(mat, node->costs);
1014 normalize_towards_target(edge);
1016 pbqp_matrix_add_to_all_rows(mat, node->costs);
1017 normalize_towards_source(edge);
1019 disconnect_edge(other_node, edge);
1022 if (pbqp->dump_file) {
1023 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1024 dump_node(pbqp->dump_file, other_node);
1028 reorder_node_after_edge_deletion(other_node);
1034 /* Add node to back propagation list. */
1035 node_bucket_insert(&reduced_bucket, node);
1038 void apply_RII(pbqp_t *pbqp)
1040 pbqp_node_t *node = node_bucket_pop(&node_buckets[2]);
1041 pbqp_edge_t *src_edge = node->edges[0];
1042 pbqp_edge_t *tgt_edge = node->edges[1];
1043 int src_is_src = src_edge->src == node;
1044 int tgt_is_src = tgt_edge->src == node;
1045 pbqp_matrix_t *src_mat;
1046 pbqp_matrix_t *tgt_mat;
1047 pbqp_node_t *src_node;
1048 pbqp_node_t *tgt_node;
1061 assert(pbqp_node_get_degree(node) == 2);
1064 src_node = src_edge->tgt;
1066 src_node = src_edge->src;
1070 tgt_node = tgt_edge->tgt;
1072 tgt_node = tgt_edge->src;
1075 /* Swap nodes if necessary. */
1076 if (tgt_node->index < src_node->index) {
1077 pbqp_node_t *tmp_node;
1078 pbqp_edge_t *tmp_edge;
1080 tmp_node = src_node;
1081 src_node = tgt_node;
1082 tgt_node = tmp_node;
1084 tmp_edge = src_edge;
1085 src_edge = tgt_edge;
1086 tgt_edge = tmp_edge;
1088 src_is_src = src_edge->src == node;
1089 tgt_is_src = tgt_edge->src == node;
1093 if (pbqp->dump_file) {
1095 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1096 dump_section(pbqp->dump_file, 2, txt);
1097 pbqp_dump_graph(pbqp);
1098 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1099 dump_node(pbqp->dump_file, src_node);
1100 dump_edge(pbqp->dump_file, src_edge);
1101 dump_node(pbqp->dump_file, node);
1102 dump_edge(pbqp->dump_file, tgt_edge);
1103 dump_node(pbqp->dump_file, tgt_node);
1107 src_mat = src_edge->costs;
1108 tgt_mat = tgt_edge->costs;
1110 src_vec = src_node->costs;
1111 tgt_vec = tgt_node->costs;
1112 node_vec = node->costs;
1114 row_len = src_vec->len;
1115 col_len = tgt_vec->len;
1116 node_len = node_vec->len;
1118 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1120 for (row_index = 0; row_index < row_len; ++row_index) {
1121 for (col_index = 0; col_index < col_len; ++col_index) {
1122 vec = vector_copy(pbqp, node_vec);
1125 vector_add_matrix_col(vec, src_mat, row_index);
1127 vector_add_matrix_row(vec, src_mat, row_index);
1131 vector_add_matrix_col(vec, tgt_mat, col_index);
1133 vector_add_matrix_row(vec, tgt_mat, col_index);
1136 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1138 obstack_free(&pbqp->obstack, vec);
1142 edge = get_edge(pbqp, src_node->index, tgt_node->index);
1144 /* Disconnect node. */
1145 disconnect_edge(src_node, src_edge);
1146 disconnect_edge(tgt_node, tgt_edge);
1152 /* Add node to back propagation list. */
1153 node_bucket_insert(&reduced_bucket, node);
1156 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1159 pbqp_matrix_add(edge->costs, mat);
1161 /* Free local matrix. */
1162 obstack_free(&pbqp->obstack, mat);
1164 reorder_node_after_edge_deletion(src_node);
1165 reorder_node_after_edge_deletion(tgt_node);
1169 if (pbqp->dump_file) {
1170 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1171 dump_edge(pbqp->dump_file, edge);
1175 /* Edge has changed so we simplify it. */
1176 simplify_edge(pbqp, edge);
1179 static void select_column(pbqp_edge_t *edge, unsigned col_index)
1182 pbqp_node_t *src_node;
1183 pbqp_node_t *tgt_node;
1189 unsigned new_infinity = 0;
1191 src_node = edge->src;
1192 tgt_node = edge->tgt;
1194 src_vec = src_node->costs;
1195 tgt_vec = tgt_node->costs;
1197 src_len = src_vec->len;
1198 tgt_len = tgt_vec->len;
1199 assert(src_len > 0);
1200 assert(tgt_len > 0);
1204 for (src_index = 0; src_index < src_len; ++src_index) {
1205 num elem = mat->entries[src_index * tgt_len + col_index];
1208 if (elem == INF_COSTS && src_vec->entries[src_index].data != INF_COSTS)
1211 src_vec->entries[src_index].data = pbqp_add(
1212 src_vec->entries[src_index].data, elem);
1217 unsigned edge_index;
1218 unsigned edge_len = pbqp_node_get_degree(src_node);
1220 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1221 pbqp_edge_t *edge_candidate = src_node->edges[edge_index];
1223 if (edge_candidate != edge) {
1224 insert_into_edge_bucket(edge_candidate);
1232 static void select_row(pbqp_edge_t *edge, unsigned row_index)
1235 pbqp_node_t *src_node;
1236 pbqp_node_t *tgt_node;
1240 unsigned new_infinity = 0;
1242 src_node = edge->src;
1243 tgt_node = edge->tgt;
1245 tgt_vec = tgt_node->costs;
1247 tgt_len = tgt_vec->len;
1248 assert(tgt_len > 0);
1252 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
1253 num elem = mat->entries[row_index * tgt_len + tgt_index];
1256 if (elem == INF_COSTS && tgt_vec->entries[tgt_index].data != INF_COSTS)
1259 tgt_vec->entries[tgt_index].data = pbqp_add(
1260 tgt_vec->entries[tgt_index].data, elem);
1265 unsigned edge_index;
1266 unsigned edge_len = pbqp_node_get_degree(tgt_node);
1268 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1269 pbqp_edge_t *edge_candidate = tgt_node->edges[edge_index];
1271 if (edge_candidate != edge) {
1272 insert_into_edge_bucket(edge_candidate);
1280 void select_alternative(pbqp_node_t *node, unsigned selected_index)
1282 unsigned edge_index;
1283 unsigned node_index;
1286 unsigned max_degree = pbqp_node_get_degree(node);
1288 node->solution = selected_index;
1289 node_vec = node->costs;
1290 node_len = node_vec->len;
1291 assert(selected_index < node_len);
1293 /* Set all other costs to infinity. */
1294 for (node_index = 0; node_index < node_len; ++node_index) {
1295 if (node_index != selected_index) {
1296 node_vec->entries[node_index].data = INF_COSTS;
1300 /* Select corresponding row/column for incident edges. */
1301 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1302 pbqp_edge_t *edge = node->edges[edge_index];
1304 if (edge->src == node)
1305 select_row(edge, selected_index);
1307 select_column(edge, selected_index);
1311 pbqp_node_t *get_node_with_max_degree(void)
1313 pbqp_node_t **bucket = node_buckets[3];
1314 unsigned bucket_len = node_bucket_get_length(bucket);
1315 unsigned bucket_index;
1316 unsigned max_degree = 0;
1317 pbqp_node_t *result = NULL;
1319 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1320 pbqp_node_t *candidate = bucket[bucket_index];
1321 unsigned degree = pbqp_node_get_degree(candidate);
1323 if (degree > max_degree) {
1325 max_degree = degree;
1332 unsigned get_local_minimal_alternative(pbqp_t *pbqp, pbqp_node_t *node)
1338 unsigned edge_index;
1339 unsigned max_degree;
1340 unsigned node_index;
1342 unsigned min_index = 0;
1343 num min = INF_COSTS;
1346 node_vec = node->costs;
1347 node_len = node_vec->len;
1348 max_degree = pbqp_node_get_degree(node);
1350 for (node_index = 0; node_index < node_len; ++node_index) {
1351 num value = node_vec->entries[node_index].data;
1353 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1354 edge = node->edges[edge_index];
1356 is_src = edge->src == node;
1359 vec = vector_copy(pbqp, edge->tgt->costs);
1360 vector_add_matrix_row(vec, mat, node_index);
1362 vec = vector_copy(pbqp, edge->src->costs);
1363 vector_add_matrix_col(vec, mat, node_index);
1366 value = pbqp_add(value, vector_get_min(vec));
1368 obstack_free(&pbqp->obstack, vec);
1373 min_index = node_index;
1380 int node_is_reduced(pbqp_node_t *node)
1382 if (!reduced_bucket) return 0;
1384 if (pbqp_node_get_degree(node) == 0) return 1;
1386 return node_bucket_contains(reduced_bucket, node);